US12123913B2ActiveUtilityA1
Diagnosis of energy storage systems during operation
Est. expiryDec 11, 2039(~13.4 yrs left)· nominal 20-yr term from priority
G01R 31/54G01R 31/3828G01R 31/392Y02E60/10G01R 31/3842G01R 31/3648
38
PatentIndex Score
0
Cited by
19
References
19
Claims
Abstract
A method for determining an open circuit voltage of an electrochemical device, including: a. collecting measurement data of the device, the measurements i. including at least the current It and the voltage Ut at the terminals of the device, ii. being time-stamped, and iii. being acquired during an uninterrupted and operational functional period of the device; b. calculating, for a plurality of times t, iv. a corrected intensity by applying a correction function to the measured intensity It, and v. an instantaneous charge based on a time series of the corrected intensity so as to obtain, for each time t, a set of collected and calculated data; c. grouping the data sets into ranges of instantaneous charge values based on the charge value of each set; and d. separately for each group, calculating an open circuit voltage of the device.
Claims
exact text as granted — not AI-modifiedThe invention claimed is:
1. A method for determining an open circuit voltage of an electrochemical device to manage said electrochemical device, implemented by a computer, the method comprising:
collecting measurement data of the device, said measurements including at least a measured current intensity I t and a measured voltage U t at terminals of the device, the measurements being time-stamped and acquired during an uninterrupted and operational functional period of the device;
calculating, for a plurality of times t,
a corrected current intensity I cor,t by correcting the measured current intensity I t , and
an instantaneous charge Q t based on a time series I cor of the corrected current intensity for the plurality of times,
to obtain, for each time t of the plurality of times t, a set of collected and calculated data I t , U t , I cor,t , and Q t ;
grouping the data sets into ranges of instantaneous charge values based on said charge value of each of the sets;
separately for each of the groups, calculating an open circuit voltage of the device by applying a deviation minimization function on each of the groups;
determining a state of health of the device, based on the calculated open circuit voltage calculated for each of the groups; and
managing the electrochemical device based on said state of health of the device.
2. The method according to claim 1 , further comprising, after calculating the open circuit voltages:
calculating the state of health of the device according to the following formula:
SOH
=
Q
1
→
2
,
age
Q
1
→
2
,
init
where Q 1→2,age corresponds to the charge difference Q between two data sets corresponding to two open circuit voltages, and
Q 1→2,init corresponds to the charge difference Q between the two data sets corresponding to the two open circuit voltages in an initial state of the device for which the state of health is considered to be maximal.
3. The method according to claim 2 , further comprising, after calculating the open circuit voltages:
subjecting the calculated open circuit voltages to an incremental capacity analysis to obtain a curve of characteristic patterns; and
comparing the obtained curve to reference curves corresponding to various states of health in order to identify the corresponding state of health.
4. The method according to claim 2 , wherein the calculating is carried out iteratively at each of the times t, and
wherein the instantaneous charge Q t is calculated based on a time series of the corrected current intensity I cor,t according to the following formula:
Q ( t )= Q ( t=t 0 )+∫ t 0 t I corr (τ) dτ
where Q(t=t 0 ) is a charge level relative to the initial charge level.
5. The method according to claim 2 , further comprising, after calculating the open circuit voltages:
comparing the calculated open circuit voltages to curves of correspondence between open circuit voltages and a state of charge in order to identify the corresponding state of charge.
6. A non-transitory computer-readable storage medium on which is stored a program for implementing the method according to claim 2 when the program is executed by a processor.
7. The method according to claim 1 , further comprising, after calculating the open circuit voltages:
subjecting the calculated open circuit voltages to an incremental capacity analysis to obtain a curve of characteristic patterns; and
comparing the obtained curve to reference curves corresponding to various states of health in order to identify the corresponding state of health.
8. The method according to claim 7 , wherein the calculating is carried out iteratively at each of the times t, and
wherein the instantaneous charge Q t is calculated based on a time series of the corrected current intensity I cor,t according to the following formula:
Q ( t )= Q ( t=t 0 )+∫ t 0 t I corr (τ) dτ
where Q(t=t 0 ) is a charge level relative to the initial charge level.
9. The method according to claim 7 , further comprising, after calculating the open circuit voltages:
comparing the calculated open circuit voltages to curves of correspondence between open circuit voltages and a state of charge in order to identify the corresponding state of charge.
10. A non-transitory computer-readable storage medium on which is stored a program for implementing the method according to claim 7 the program is executed by a processor.
11. The method according to claim 1 , wherein the calculating is carried out iteratively at each of the times t, and
wherein the instantaneous charge Q t is calculated based on a time series of the corrected current intensity I cor,t according to the following formula:
Q ( t )= Q ( t=t 0 )+∫ t 0 t I corr (τ) dτ
where Q(t=t 0 ) is a charge level relative to the initial charge level.
12. The method according to claim 11 , wherein the calculating further comprises:
calculating a state of charge according to the following formula:
SOC
i
-
SOC
i
-
1
+
∫
i
-
1
i
α
(
I
i
)
dt
Q
max
,
i
-
SOC
i
-
1
+
∫
i
-
1
i
I
corr
dt
Q
max
,
i
where the index i represents the iteration and α represents a correction function.
13. A non-transitory computer-readable storage medium on which is stored a program for implementing the method according to claim 12 the program is executed by a processor.
14. The method according to claim 11 , further comprising, after calculating the open circuit voltages:
comparing the calculated open circuit voltages to curves of correspondence between open circuit voltages and a state of charge in order to identify the corresponding state of charge.
15. A non-transitory computer-readable storage medium on which is stored a program for implementing the method according to claim 11 the program is executed by a processor.
16. The method according to claim 1 , further comprising, after calculating the open circuit voltages:
comparing the calculated open circuit voltages to curves of correspondence between open circuit voltages and a state of charge in order to identify the corresponding state of charge.
17. The method according to claim 1 , further comprising, after calculating the open circuit voltages, calculating the state of health of the device by at least one of the following operations:
comparing the obtained open circuit voltages to open circuit voltages obtained by a plurality of laboratory aging tests on said device,
comparing the obtained open circuit voltages to open circuit voltages obtained by a plurality of laboratory aging tests on a device of a model similar to said device, and
comparing the obtained open circuit voltages to open circuit voltages obtained by a previous implementation of the method on said device.
18. A computer program product embodied on a non-transitory computer-readable medium, the computer program product comprising instructions for implementing the method according to claim 1 when this program is executed by a processor.
19. A non-transitory computer-readable storage medium on which is stored a program for implementing the method according to claim 1 when the program is executed by a processor.Cited by (0)
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